Core assembly for a heat exchanger and method of assembling

ABSTRACT

A core assembly for a heat exchanger includes a plurality of parting sheets defining a plurality of fluid passages including a plurality of first fluid passages and a plurality of second fluid passages arranged in an alternating arrangement, wherein each of the plurality of parting sheets comprises a thickness of about 0.016″. Also included is a plurality of first fluid passage fins disposed between the plurality of parting sheets within each of the plurality of first fluid passages. Further included is a plurality of second fluid passage fins disposed between the plurality of parting sheets within each of the plurality of second fluid passages. Yet further included is a plurality of closure bars disposed between respective pairs of the plurality of parting sheets.

BACKGROUND OF THE INVENTION

The present invention relates to heat exchanger arrangements, and moreparticularly to a core assembly for a heat exchanger.

A heat exchanger is utilized to cool or heat a fluid medium by flowingtwo fluid mediums adjacent to each other through a core assembly. Theheat exchanger may be employed in various applications and subjected tospecific thermal requirements. The dimensions of the components of theheat exchanger, and more particularly the core assembly play asignificant role in meeting the operating requirements and inwithstanding the thermal requirements noted above.

BRIEF DESCRIPTION OF THE INVENTION

According to one embodiment, a core assembly for a heat exchangerincludes a plurality of parting sheets defining a plurality of fluidpassages including a plurality of first fluid passages and a pluralityof second fluid passages arranged in an alternating arrangement, whereineach of the plurality of parting sheets comprises a thickness of about0.016″ (about 0.406 mm) Also included is a plurality of first fluidpassage fins disposed between the plurality of parting sheets withineach of the plurality of first fluid passages. Further included is aplurality of second fluid passage fins disposed between the plurality ofparting sheets within each of the plurality of second fluid passages.Yet further included is a plurality of closure bars disposed betweenrespective pairs of the plurality of parting sheets.

According to another embodiment, a method of assembling a heat exchangeris provided. The method includes stacking a plurality of first finshaving a fin height of about 0.088″ (about 2.24 mm), a plurality ofsecond fins having a fin height of about 0.324″ (about 8.23 mm), atleast one closure bar within a plurality of parting sheets. The methodalso includes applying a brazing material to the plurality of partingsheets. The method further includes heating the core assembly toactivate the brazing material and adhere the plurality of fins, the atleast one closure bar and the plurality of parting sheets to each other.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter which is regarded as the invention is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other features and advantages ofthe invention are apparent from the following detailed description takenin conjunction with the accompanying drawings in which:

FIG. 1 is a front perspective view of a heat exchanger;

FIG. 2 is front elevational view of the heat exchanger;

FIG. 3 is a top elevational view of the heat exchanger;

FIG. 4 is a schematic illustration of a core assembly of the heatexchanger;

FIG. 5 is a schematic illustration of a first fluid passage of the coreassembly; and

FIG. 6 is a schematic illustration of a second fluid passage of the coreassembly.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1-3, a heat exchanger 10 is illustrated. The heatexchanger 10 may be used in conjunction with an assembly or system of avehicle, such as an aircraft, however, it is contemplated that othervehicles may benefit from the embodiments described herein. In oneembodiment, the heat exchanger 10 is part of an air conditioning systemor refrigeration system of an aircraft. In particular, a galley coolingrefrigeration unit may employ the heat exchanger 10 for coolingpurposes.

The heat exchanger 10 includes a core assembly 12 disposed within ahousing 14. The core assembly 12 is formed of a width W, a length L, anda height H. In one embodiment, the core assembly 12 is formed ofvolumetric dimensions of about 4.0″×14.4″×10.1″ (about 10.2 mm×36.6mm×25.7 mm) The housing 14 includes a first fluid inlet 16 for a firstfluid 18, such as a liquid. The first fluid 18 exits through a firstfluid outlet 20. Additionally, the housing 14 is configured to allow asecond fluid 21, such as ram air, to pass through the core assembly 12in a cross-flow manner, with respect to the first fluid 18. The coreassembly 12 defines a plurality of first fluid passages 22 and aplurality of second fluid passages 24 for the first and second fluids18, 21. In one embodiment, the number of the plurality of first fluidpassages 22 is twenty-two (22), while the number of the plurality ofsecond fluid passages 24 is twenty-three (23).

Referring to FIGS. 4-6, each of the plurality of first and second fluidpassages 22, 24 are interspersed within the core assembly 12 to providefor thermal communication and transfer between the first and secondfluids 18, 21. Each of the plurality of first and second fluid passages22, 24 are defined by parting sheets 26 on two sides and by closure bars28 on two sides. In one embodiment, the parting sheets 26 have athickness of about 0.016″ (about 0.406 mm) The closure bars 28 provide adesired support structure for the core assembly 12.

A plurality of first fins 30 is disposed within the plurality of firstfluid passages 22 between corresponding pairs of the parting sheets 26.Similarly, a plurality of second fins 32 is disposed within theplurality of second fluid passages 24 between corresponding pairs of theparting sheets 26. The fins 30, 32 are shaped to have alternating peaksthat extend between corresponding parting sheets. In one embodiment, thefins 30, 32 are formed in a “ruffled” geometry along a continuous sheetwithin each of the plurality of fluid passages 22, 24. Although thecontemplated dimensions of the fins 30, 32 may vary, in one embodiment,each of the plurality of first fluid passage fins 30 comprises a finheight of about 0.088″ (about 2.24 mm) and a fin thickness of about0.004″ (about 0.102 mm) The continuous sheet of each of the plurality offirst fluid passage fins 30 comprises a fin density of about 30 fins perinch. In one embodiment, each of the plurality of second fluid passagefins 32 comprises a fin height of about 0.324″ (about 8.23 mm) and a finthickness of about 0.003″ (about 0.076 mm) The continuous sheet of eachof the plurality of second fluid passage fins comprises a fin density ofabout 26.5 fins per inch.

Each of the plurality of second fluid passages 24 include a guard fin 34proximate a leading edge 36 and a trailing edge 38 of the direction offluid flow. The guard fin 34 protects the plurality of second fins 32against handling damage during processing, installation and aggressivecleaning and to protect against foreign object damage (FOD) and finerosion during service. In one embodiment, the guard fin 34 comprises afin height of about 0.324″ (about 8.23 mm), a fin thickness of about0.012″ (about 0.305 mm), and a fin length of about 0.250″ (about 6.35mm)

The core assembly 12 is assembled by stacking the plurality of firstfins 30 and the plurality of second fins 32, the closure bars 28 withinthe parting sheets 26. A brazing material is utilized on the partingsheets 26 to attach each part to adjacent joining parts. Accordingly,the interface between each of the closure bars 28, the parting sheets 26and the fins 30, 32 fit within each other. Once the parts comprising thecore assembly 12 are inter-fit within each other with the brazingmaterial disposed at each interface with the parting sheets 26, the coreassembly 12 is heated to activate the brazing material and adhere theseveral core assembly parts together. The described assembly method forthe core assembly 12 is only one such example of a fabrication techniquethat will benefit from the disclosure and application of this invention.

While the invention has been described in detail in connection with onlya limited number of embodiments, it should be readily understood thatthe invention is not limited to such disclosed embodiments. Rather, theinvention can be modified to incorporate any number of variations,alterations, substitutions or equivalent arrangements not heretoforedescribed, but which are commensurate with the spirit and scope of theinvention. Additionally, while various embodiments of the invention havebeen described, it is to be understood that aspects of the invention mayinclude only some of the described embodiments. Accordingly, theinvention is not to be seen as limited by the foregoing description, butis only limited by the scope of the appended claims.

1. A core assembly for a heat exchanger comprising: a plurality of parting sheets defining a plurality of fluid passages including a plurality of first fluid passages and a plurality of second fluid passages arranged in an alternating arrangement, wherein each of the plurality of parting sheets comprises a thickness of about 0.016″; a plurality of first fluid passage fins disposed between the plurality of parting sheets within each of the plurality of first fluid passages; a plurality of second fluid passage fins disposed between the plurality of parting sheets within each of the plurality of second fluid passages; and a plurality of closure bars disposed between respective pairs of the plurality of parting sheets.
 2. The core assembly of claim 1, wherein each of the plurality of first fluid passage fins comprises a continuous sheet including a ruffled fin geometry and a plurality of alternating peaks extending between corresponding parting sheets.
 3. The core assembly of claim 2, wherein the continuous sheet of each of the plurality of first fluid passage fins comprises a fin height of about 0.088″ and fin thickness of about 0.004″.
 4. The core assembly of claim 2, wherein the continuous sheet of each of the plurality of first fluid passage fins comprises about 30 fins per inch.
 5. The core assembly of claim 1, wherein each of the plurality of second fluid passage fins comprises a continuous sheet including a ruffled fin geometry and a plurality of alternating peaks extending between corresponding parting sheets.
 6. The core assembly of claim 5, wherein the continuous sheet of each of the plurality of second fluid passage fins comprises a fin height of about 0.324″ and a fin thickness of about 0.003″.
 7. The core assembly of claim 5, wherein the continuous sheet of each of the plurality of second fluid passage fins comprises about 26.5 fins per inch.
 8. The core assembly of claim 1, further comprising a plurality of guard fins disposed proximate a leading edge and a trailing edge of the plurality of second fluid passage fins.
 9. The core assembly of claim 8, wherein each of the plurality of guard fins comprises a fin height of about 0.324″, a fin thickness of about 0.012″, and a fin length of about 0.250″.
 10. The core assembly of claim 1, wherein the plurality of first fluid passages comprises a plurality of liquid passages and the plurality of second fluid passages comprises a plurality of ram air passages.
 11. The core assembly of claim 10, wherein the plurality of liquid passages comprises about 22 passages and the plurality of ram air passages comprises about 23 passages.
 12. The core assembly of claim 1, wherein the heat exchanger is disposed on an aircraft.
 13. The core assembly of claim 12, wherein the heat exchanger is in operative association with a galley refrigeration unit.
 14. A method of assembling a heat exchanger comprising: stacking a plurality of first fins having a fin height of about 0.088″, a plurality of second fins having a fin height of about 0.324″, at least one closure bar within a plurality of parting sheets; applying a brazing material to the plurality of parting sheets; and heating the core assembly to activate the brazing material and adhere the plurality of fins, the at least one closure bar and the plurality of parting sheets to each other. 